Compressed-air brake.



w Tit No..'884,-364. PATENTED APR. 14. 1908.

A. GHANDESON.

COMPRESSED AIR BRAKB. 4

APPLIOATIONTILED NOV.261907.

6 SHEETS-SHEET 1.

No. 884,364. V PATBNTED' APR. 14, 19-08.

- A. GHANDESON. 4

COMPRESSED AIR BRAKE.

APPLIOATION PILED NOV. 26.1907.

' B SHEETS-SHEET 2.

ru: NORRIS FETERS :04. wAsHNoroN. n. c.

No. 884,364.- PATENTED APR. 14, 1908.

- A. GHANDBSON.

COMPRESSED AIR BRAKB( APPLIOATION PILED NOV.26.1907.

6 SHEETS-SHEET 4.

/NvEA/T 'PATENTED APR. 14, 1908.

6 SHEETS-SHEET 6.

A. GHANDESON. OOMPRESSBD AIR BRAKE. APPLIOATIOKFILED NOV.26.1907.

UNITED STATES PATENT OFFICE.

ALFRED CHANDESON OF JETTE ST. PIERRE, BELGIUM, ASSIGNOR TO COMPAGNIE INTER- NATIONALE DE FREINAGE (SYSTEME LUYERS) GIUM.

SOCIT ANONYME, OF BRUSSELS, BEL- COMPBESSED-AIR BRAKE.

No. &84,364.

Patented Aprl 14, 1908. Serial No. 4o3,9o3.

To all whom it may concern:

Be it known that I, ALFRED CHANDESON, a subject of the King of the Belgians, residing at J ette St. Pierre, Belgium, have invented neW and useful Improvements in Compressed- Air Brakes, of which the following is a specification.

This invention relates to compressed air brakes for railway trains in which a fall of pressure in the train pipe, puts auxiliary compressed air reservoirs in communication With the brake cylinders in such a Way that the pistons of these cylinders actuated by' the compressed air from the reservoirs bring about the application of the brake shoes or blocks.

The object of this invention is to provide apparatus intended to accelerate the emptying of the train pipe, to regulate the supply of compressed air from the auxiliary reservoirs to the brake cylinders, and the emptying of the latter.

Apparatus according to this in'venticn enables fresh quantities of air to be introduced into the brake cylinders When the brakes are already applied, Without first having to reestablish the normal pressure in the train pipe and auxiliary reservoirs and the apparatus is so designed that after an application of the brakes, or after each increase in the degree of application of same the pressure produced in the brake cylinders is maintained so long as the train pipe is not again supplied With air, so that if a leakage occurs in the train pipe While the brakes are on, or even if the train pipe should get broken and be completely emptied, the brakes Will not be taken off.

The apparatus comprises in combination; an emptying accelerator. j oined onto the train pipe, a distributer connecting the auxiliary reservor to the brake cylinder, and an evacuator for emptying this cylinder, all three Working conjointly.

The accompanying draWings illustrate by Way of example one Construction of apparatus according to this nvention.

Figures 1 and 2 are longitudinal sections thereof along two planes perpendicular to each other. Fig. 3 is a transverse section corresponding to the line A-A of Fig. 2. Figs. 4 and 5 are transverse sections corresponding to the lines B-B and C-C respectively of Fig. 1.' Fig. 6 is a transverse section corresponding to the line D-D Fig.

2. Figs. 7 to 10 are diagrammatic views indicating the positions occupied by the slide valves at different moments of the application of the brakes; Fig. 7 When the brakes are taken off and the air in the train pipe is at normal pressure; Fig. 8 at the commencement of the depression in the train pipe; Fig. 9 during the depression and before the expansion of the air in the reservoir can have produced the equilibrium of pressure in the said reservoir and the train pipe; Fig. 10 after this equilibrium is established.

1 is the air chamber of the accelerator connected directly to the train pipe 4 from Which it can be shut oli" by a cock 5. This chamber comprises a cylindrical portion and a portion 6 of truncated cone shape Which is j oined 'to a portion 7 of truncated cone form of the air chamber' 2 of the distributer and separated from it by a caoutchouc diaphragm 8 forming a fluid tight partition between the two'chambers.

The chamber 2 of the distributer is in free communication With an auxiliary reservoir iadapted to supply the brake' cylinder, and

ith supplementary reservoirs adapted to augment When needed the capacity of the auxiliary reservoir. These I'eservoirs for the sake of olearness are not shown in the drawings. The chamber 2 of the distrbuter is joined to the air chamber 3 of the evacuator from which it is separated by a piston 11 that is furnished With a packing ring and formed With a small hole 32.

The valve seat portion of the chamber l is formed With ports 12and 28 communicating directly With the atmosphere, and With a port 13'Which by a pipe 14 connects the said chamber With the chamber 3 of the evacuator. Over these ports Works a slide valve 15 which is pressed onto its seat by a spring and connected to the central part of the daphragm 8 by a rod 16 which extends through the diaphragm into the distributer Where the extremity of this extension 17 is attached to a slide valve 18 likeWise held' down upon its seat by a spring. The seat of the slide valve 18 is formed With ports 19 and 22. By the ports 19 the chamber 2 can communicate through a pipe 20 With the brake cylinder. The slide valve 18 is formed With a port 21 adapted to coincide With one of the ports 19. By the port 22 the chamber 2 can communicate through a pipe 23 With the part 6 of the chamber 1 of the accelerator.

The rod of the piston 11 which separates the chamber 3 from the chamber 2 connects this piston to a slide valve 24 pressed by a spring onto its seat which is 'ormed with ports 25, 26 and 29. The port 25 communicates directly with the atmosphere the port 26 communicates With the br'ake cylinder through a pipe 27 and the pipe 20, and the g ort 29 connects the chamber 3 to the pipe 14 lbading from the chamber 1. A branch 30 of this pipe 14 opens freely into the chamber 3 and in this branch is located a non-return valve 31 held down upon its seat by a light spring as shown in Fig. 3. The capacity of the chamber 3 of the evacuator must be very small in comparison with that of the chamber 2 and of the auXiliary reservoir which communicates freely therewith.

The apparatus works as follows:--VVhen the brakes are taken oil and the air pressure in the train pipe is maintained normal, the parts occupy the positions indicated in Figs. 1 and 7. The train pipe 4 communicates through the chamber 1 of the accelerator, the pi e 14 and the port 29 with the chamber 3 of t e evacuator and by the port 22 and pipe 23 with the chamber 2 of the distributer and its auxiliary reservoir. The slide valve 15 intercepts the communications with the atmosphere of'the chamber 1- through the port 12, and of the chamber 3 of the evacuator through theport 28; the slide valve 18 intercepts the communication between the chamber 2 and the brake cylinder and' the slide valve 24 puts the brake cylinder in communication with the atmosphere.

When the driver produces a sudden diminution of pressure in the train pipe 4 in order to put on the brakes this reduction of pressure is first transmitted to the chamber 1 and as the pressure in the chamber 2 remains higher the excess of pressure Will cause the diaphragm 8 to bend towards the chamber 1 into the position indicated in Fig. 8. In bending it pushes back the slide valve 15 and draws the slide valve 18 forward the eflect of this being to first of all close the port 22 and to thus intercept all communication between the chambers 2 and 1, then to put the chamber 3 into communication with the atmosphere'through the port 29, the pipe 14, the port 13 and the port 28. In this position the chamber 3 empties 'itself and the pressure which obtains in the chamber 2 thrusts back the piston 11 and consequently the slide valve 24 which closes the communications between the chamber 3 and the pipe 14 and between the brake cylinder and the atmosphere, but the chamber 3 remaining in communication with the chamber'2 throu h the hole 32 in the piston 11, equilibrium oi ressure is restablished between these two cl iambers as soon as the former is no longer in communication with the atmosphere, the valve 31 being held on its seat until the engine driver recharges the train pipe. The bending of the diaphragm continues until it takes up the position shown in Fig. 9 in which the slde valve 15 uncovers the port 12 and so puts the chamber 1 and consequently the train pipe 4 into communication with the atmosphere, while the slide valve 18 uncovers the ports 19 and permits the air from the chamber 2 and from the auxiliary reservoir to ex and into the brake cylinder through the pipe 20 to put on the brakes. The effect of this eXpansion is to rapidly dimnish the ressure in the chamber 2 and as soon as it ecomes reduced to the same degree as in the chamber 1, the diaphragm straightens itself again as shown in Fig. 10 and brings back the slide valves 15 and 18 into their original positions, cutting off the communication between the chamber 2 and the atmosphere and reestablishing the communication between the chambers 2 and 1 by the pipe 23 and the port 22. The air in these three chambers is thus brought and maintained at equal pressure as long as the brakes remain on. When the driver restablishes the normal pressure in the train pipe to take the brakes off this pressure is restablished in the chamber 1, in the chamber 2 by the pi e 23, and in the chamber 3 by the pipe 14 an the non-return valve 31, but as the chamber '3 is much smaller than the chamber 2 the augmentation of pressure therein is much more rapid and the momentary eXcess of pressure thrusts the piston 11 back towards the chamber 2 and opens the slide valve 24 thereby-uncovering the port 29 and putting the brake cylinder into communication with the atmosphere bythe ports 26 and 25. The emptying of the brake cylinder takes the brakes off and the parts again assume the positions indicated in Fig. 1.

It has been hereinbefore set forth that When the brakes are being applied the communication between the auXiliary reservoir and the brake cylinder is closed as soon as the latter has received a sufiicient quantity of air for the pressure in the reservoirto again be in equilibrium with the reduced pressure in the train-pipe. This admission of air into the cylinder sets up a greater or less pressure in same according to the reduction of pressure that the engine-driver has caused to obtain in the train-pipe and according to the relative capacities of the reservoir and of the cylinder. These capacities are so calculated that after a normal application of the brakes there shall still be a very considerable eXcess of pressure in the reservoir and it follows from this that the pressure can be increased in the cylinder by introducing fresh quantities of air into same without first having to recharge the train-pipe and the reservoir. Thus when the brakes are on and the parts consequently occupy the positionsshown in Fig. 10, if a new sudden depression is created `'in the train-pipe, the diaphragm 8 will again &84,364

bend towards the chamber l, putting this chamber into communication with the atmosphere through the port 12 and putting the chamber 2 of the reservoir into'communication with the brake cylinder through the ports 19 after having cut off the chamber 2 from the chamber 1 through the closing of the port 22.

Owing to the small capacity of the chamber 3, the eXpansion of the air of the reservoir in the brake cylinder will not have any eflect on the piston 11, since the small hole 32 Will suflice to maintain an equal pressure between the chambers 2 and 3. The ports 26 and 29 will therefore remain shut. The eX- pansion'of the air of the reservoir in the brake cylinder will promptly bring about a new equilibrium of pressures in the chambers 2 and 1 and consequently cause the diaphragm 8 to be straightened, which in turn will bring about the closing of the ports 19 and 22 and of the port 12. The same operation may be repeated so longas there is not an equilibrium of pressure between the reservoir, the train-pipe and the brake cylinder. On the other hand if the sudden depression in the train-pipe, instead of being due to a manipu lation on the part of the engine-driver, arose for instance from a breakage 'of the trainpipe capable of causing the complete and immediate emptying of the latter, the result would be that after having been deflected towards the chamber 1 so as to put the chamber 2 into communication with the brake cylinder, the diaphragm would no longer be able to straighten itself again, and thus equilibrium of pressure Would be established between the cylinder and the chambers 2 and 3, the parts remaining in the position shown in Fig. 9 and the brakes remaining on. If instead of a breakage of the train-pipe, a leakage should occur in the latter when the brakes are on, the progressive diminution of pressure that Would result therefrom would extend to the chamber 2 through the conduit 23 and to the chamber 3 through the small hole 32 without affecting the position of the diaphragm and of the distributing slidevalves.

Having now described my invention, What I claim as new and desire to secure by Letters Patent is 1. Apparatus for supplying compressed air to and emptying the brake cylinder of a compressed air brake and for accelerating the operation of said brake, comprising in combination a branch of the train pipe, an auXiliary reservoir for supplying compressed air to the brake cylinder, a fieXible diaphragm separating said reseryoir from said branch of the train pipe and a pipe connecting the same together, a small chamber contiguous to the auxiliary reservoir a movable piston pierced with a small hole separating said small chamber from said auXiliary reservoir, a pipe and a branch pipe both connecting said small chamber with the train pipe, a non return valve located in said branch pipe, connections between the brake-cylinder, the train pipe and the small chamber respectively and the atmosphere, means for simultaneously putting the train pipe into communication with the atmosphere, cutting off communication between said train pipe and the auxiliary reservoir, putting the latter into communication with the brake cylinder and cutting off communication between said cylinder and the atmosphere whenever the pressure in the train pipe is suddenly reduced and for simultaneously cutting o'l'l' communication between the auxiliary reservoir and the brake cylinder and putting the said reservoir into communication with the train pipe as soon as equilibrium of pressure is restablished between the train pipe and said reservoir, and means for putting the brake cylinder into communication with the atmosphere only when the train ipe is recharged with compressed air.

2. pparatus for supplying compressed air to and emptying the brake cylinder of a compressed air brake and for accelerating the operation of said brake comprising in combination a first chamber communicating freely with the train pipe, a second chamber communicating freely with the auxiliary reservoir that supplies compressed air to the brake cylinder, a fiexible partition between said first and second chambers and a pipe connecting the same together, a third chamber of small Capacity contiguous to said second chamber, a movable piston pierced with a small hole forming a partition between said second and third chambers, a pipe connecting said third chamber with the first chamber, a branch of said pipe connecting the same With the third chamber, a non return ValVe in said branch pipe, connections between the brake cylinder, the first chamber and the third chamber with the atmosphere respectively, means for simultaneously putting the first chamber into communication with the atmosphere, cutting off communication between the first and second chambers, puttin the latter into communication with the bra he cylinder and cutting oli communication between said cylinder and the atmosphere when a sudden reduction of pressure occurs in the train pipe and for simultaneously cutting off communication between the second chamber and the brake cylinder and putting said second chamber into communication with the first chamber as soon as the pressure in the second chamber becomes again equal to the pressure in the first chamber and means for opening the brake cylinder to the atmosphere only When a rise of pressure occurs in the first chamber. 3. Apparatus for supplying com ressed air to and emptying the brake cylindbr of a compressed air brake and for accelerating the operation of said brake, comprising in combination a first chamber in free communication with the train pipe, a second chamber in free communication with the auxiliary reservoir of the brake cylinder, a fiexible partition between said chambers and a pipe connecting the same together, a third chamber of small Capacity contiguous to the second chamber a movable piston pierced with a small hole forming a partition between said second and third chambers, a pipe connect'- ng the rear part of said third chamber with the first chamber, a by-pass between said pipe and the fore part of said third chamber, a non return valve in said by-pass, ducts connecting the brake cylinder, the first chamber and the third chamber respectively with the atmosphere, means for simultaneously opening the first chamber to the atmosphere, cutting off communication between the first and second chambers, putting the second chamber into communication with the brake cylinder and cutting oli communication between the latter and the atmosphere when a sudden fall of pressure occurs in the train pipe and whenever a further sudden 'fall of ressure occurs therein without the same aving been recharged with compressed air, and for simultaneously cutting off the brake cylinder from the auxiliary reservor and putting the latter into communication with the train pipe as soon as and whenever the pressure becomes equal in said reservoir and said train pipe, and means for putting the brake cylinder into communication with the atmosphere only on the train pipe being recharged with compressed air.

4. Apparatus for supplying compressed air to and emptying the brake cylinder of a compressed air brake, comprising in combination a first chamber opening freely into the train pipe, a second chamber opening freely into the auXiliary reservoir of the brake cylinder, a fiexible partition between the said first and second chambers and a pipe connecting said chambers together, a third chamber of small capacity contiguous to the second chamber, a movable piston perced with a small hole forming a partition between said second and third chambers, a double branched pipe connecting both the rear and front parts of said third chamber with the first chamber, a non-return valve in one branch of said pipe, a slide Valve in the first chamber and a seat for the same formed with ports communicating with the said double branched pipe and capable of being connected with one of the ports opening to the' atmosphere through a groove in said slide valve and a rigid connection between 'the latter and the middle of the fiexible partition, a slide valve in' the second chamber and a seat for the same formed with ports eommunicating with the brake cylinder and with the pipe connecting the first and second chambers together respectively and a rigid connection between said slide-valve and the middle of the fieXible partition, a slide-valve in the third chamber and a seat for the same formed with ports communicating with the Valveless branch of the double branched pipe, with the atmosphere and with the brake cylinder respectively, the two latter ports being capable of connection together through a groove in the' slide-valve, and a rigid connection between said slide-valve and the aforesai'd movable piston.

In testimony whereof I have affixed my signature in presence of two subscribing witnesses.

ALFRED CHANDESON.

Witnesses:

A. T. E. KIRKPATRICK, AD. VOGEL; 

